Improvement in furnaces for burning pulverulent fuel



M. FERRET.

FURNACE FOR BURNING PULVERULENT FUEL.

Patented March 28 N PEITER$YPNOTOLITHOGRAPHER. WASHINGTON. D C.

-Paris, France, have invented certain new and,

' which cannot previous preparation of the same, even though it be extremely poor and thin.

in which-the same is or may be carried into 1 2 Fig. 2. Fig. 2 is alongitudinal section on appear.

N E STATES MICHEL FERRET, or PARIS, FRANCE.

IMPROVEMENT IN FURNACES FOR BURNING PULVERULENT FUEL.

Specification forming part of Letters Pa To all whom it may concern.- 7

Be it known that I, Mionnr. FERRET, of

useful Improvements in Furnaces for Burning Pulverulent and Poor Fuel, of which the following is a specification: Most kinds of fuel offer the greatest obstacle. to combustion when in a pulverulent condition. Natural agglutination, when exposed to fire, is the property of but few kinds of fuel, and artificial agglutination is a costly process, practically be applied to poor combustibles.

To remedy these difficulties 1 have devised a furnace in several stories or floors, (foyer 2itages,) which fulfills the double purpose of burning pulverulent or poor fuel without any The nature of my invention, and the manner effect, will be understood by reference to the accompanying drawing, in which I have represented two forms of storied and gas-generating furnace embodying my invention, the first constructed to operate upwardly or per ascensum, and the second downwardly or 1961' decensum.

The first is adapted principally for the combustion of non-fiambant fuel. The second is for use in case of the reduction of oxides, or the employment of flambant fuel, with a view of obtaining combustion of smoke.

Figure 1 is a transverse section on the line the lines 3 4, Figs. 1 and 3. Fig. 3 represents horizontal sections on the lines 5 6 and 7 8 Fig. 2.

These three figures relate to the principal arrangement, which I have denominated per ascensmn, for reasons which will hereafter Fig. 4 represents a longitudinal vertical section of a furnace operating downwardly, or per decensum.

These two arrangements differ from each other only in the direction of movement of the air-current or draft. The arrows in full lines indicate the course of the air, and those in dotted lines the course of the fuel.

Each furnace is composed of four supertent No. 175,493, dated March 28, 1876 application filed February 19, 1876.

posed floors or hearths, a 1) 0d, of refractory earth,.and an ash-pit, 6. Three doors,f g h, permit of access to the interior of the furnace. To put in operation a furnace of this kind, all the floors must first be brought to a red heat by means of wood or charcoal. The furnace is then charged on all its floors or hearths with the fuel which it is proposed to burn. When combustion is well established, the fire is managed as follows: The ashes on the hearth port combustion is' introduced by channels I,

where it becomes heated in descending the length of the furnace-walls. The combustion is thus maintained by heated air. .The gases of combustion pass into the gas-generatorA, through the 'mass of fragmentary fuel contained therein, and pass out therefrom through the burner-flues B. The hearth a in Fig. 2 is formed of two layers or thicknesses, between which is a space into which air enters through lateral channels D. This air becomes heated, and is conducted through channels E to the burnerflues B, where it serves to inflame the products of combustion of the gas-genera tor. This double hearth possesses, moreover, the advantage of preventing the fusion of the hearth-slabs placed at the point where the temperature is most elevated.

The above description refers to the furnace operating per -,as0ensum.

In the one operating per decensmn all the members of the furnace are the same, and the only difference is in their respective positions and in the direction of movement of the air, which, like the fuel, descends through the several stories of the furnace. This will be seen by reference to Fig. 4 of the drawing, and it will also be noted that the floor b is the one which, in this instance, is formed of two layers or thicknesses between which the air is heated, and thence passes to the burning-fines B.

operated either by the hand or mechanically.

The same result, however, can be arrived at by the employment of movable hearths or surfaces, operating to automatically displace the fuel.

' The fuel can be renewed whenever necessary, and the interval of time between each charge may be varied at will, and may extend even to twelve hours by suitably regulating the draft. Owing to the widespread surfaces of the several hearths, the most finely-powdered fuel can be burned. By bringing the surfaces of the hearths comparatively close together, the temperature is elevated, and effects the combustion of the densest and poorest substances. By heating the air that supports combustion, incineration is pushed to the extreme limit. In this way I can burn to r a condition completely pulverulent anthracite, poor bituminous coal, coke, peat, saw-dust,

and even the residuum of other furnaceswhich expresses the limit of poverty that can be attained. This facility in burning inferior co'mbustibles, admits of economically bringing v to high temperatures every kind of substance by mixing with such substance a suitable proportion of combustible matter; and in case the substances are oxides reducible by coal, the apparatus can operate as a reducing-furnace. In this case the draft should be downwardly, or as in Fig. 4:. The air is introduced from above, in order that the gases in acconr panying the charge through the several stories may become more and more reducing in character.

My furnace, therefore, according to the way in which it is worked, can be made to produce carbonic acid and oxide of carbon in varied proportions, with a greater or less mixture of atmospheric air.

With a view of obtaining much heat and of producing gasification of all kinds of combustible matter, I combine, as shown, my apparatus for consuming pulverulent fuel with a gas-generator for containing fuel in fragmentary form. The gases produced by the first pass through the fragmentary mass contained in the gas-generator, in orderto absorb the excess of air .to decompose the carbonic-acid gas, and to thus produce oxide of carbon, the ulterior combustion of which produces the maximum useful'effect. In some cases, particularly where'a comparatively low but constant temperature is required, as in heaters of all kinds, the gasgenerator may be dispensed with, using onlythe furnace with its several stories, operating either per ascensum or per descensum, or, it necessary, having the two modes combined in one furnace, which would permit of its use in either way at pleasure.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. A furnace or apparatus for burning poor or pulverulent fuel, provided with a series of superposed communicating hearths, and with draft-fines arranged and operating to maintain an air-current upward or downward through the furnace, substantially as set forth.

2. The combination of a furnace or apparatus for burning poor or pulverulent fuel on a series of superposed communicating hearths, as described, with a gas-generator for burning fragmentary fuel, substantially as set forth.

In testimony whereof I have signed my name to this specification before two subscribing witnesses.

MICHEL FERRET.

Witnesse s:

ALBERT ROBIN, ALFRED Oonvv. 

